U.S. patent number 6,023,392 [Application Number 09/016,351] was granted by the patent office on 2000-02-08 for hard disk drive cover having improved structural and production characteristics.
This patent grant is currently assigned to SamSung Electronics Co., Ltd.. Invention is credited to Youn-Tai Kim.
United States Patent |
6,023,392 |
Kim |
February 8, 2000 |
Hard disk drive cover having improved structural and production
characteristics
Abstract
A hard disk drive cover is constructed using plastic resin that
is injection molded to form the cover. Increased dimensional
precision is attained by using injection molded plastic methods.
The plastic resin cover is able to attain the requisite rigidity
needed to endure vibration by using an inserted reinforcing frame.
The rigidity increases the ability of the hard disk drive to endure
vibrations and other disturbances, while the decrease in weight,
due to use of a plastic resin to form the cover, causes the
resonance point to increase. This improves the vibrational
characteristics of both the cover and the hard disk drive.
Furthermore, the present invention reduces manufacturing costs by
eliminating the need to machine the cover prior to assembly and
also eliminating the need to apply a special anti-corrosive coating
to the cover.
Inventors: |
Kim; Youn-Tai (Seoul,
KR) |
Assignee: |
SamSung Electronics Co., Ltd.
(Kyungki-do, KR)
|
Family
ID: |
19495953 |
Appl.
No.: |
09/016,351 |
Filed: |
January 30, 1998 |
Foreign Application Priority Data
|
|
|
|
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Jan 30, 1997 [KR] |
|
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97-2764 |
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Current U.S.
Class: |
360/99.18;
G9B/33.024; G9B/25.003; 29/603.03 |
Current CPC
Class: |
G11B
25/043 (20130101); G11B 33/08 (20130101); Y10T
29/49025 (20150115) |
Current International
Class: |
G11B
25/04 (20060101); G11B 33/08 (20060101); G11B
005/012 () |
Field of
Search: |
;360/97.01,97.03,98.01
;361/685,739 ;29/603.03 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Davis; David D.
Attorney, Agent or Firm: Bushnell, Esq.; Robert E.
Parent Case Text
CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein,
and claims all rights accruing thereto under 35 U.S.C. .sctn.119
through my patent application entitled Cover Assembly Having Frame
for Hard Disk Drive earlier filed in the Korean Industrial Property
Office on the 30th day of January 1997 and there duly assigned Ser.
No. 1997/2764.
Claims
What is claimed is:
1. A cover connected to a base for a hard disk drive,
comprising:
said base having a mounted hard disk drive assembly comprising an
actuator, a motor driving said actuator, a disk for storing data,
and a head supported on said actuator for reading data from said
disk;
a frame reinforcing said cover, said frame having a plurality of
elongated bands that extend radially outward to engage a plurality
of edges of said cover, each of said elongated bands having a
perforation in a distal end of said each of said elongated bands to
fastenably engage with said base; and
said cover constructed of an injection molded plastic resin
material, said cover being molded around an end of each of said
elongated bands, said cover having a plurality of bores that align
with said perforation in said distal end of each of said elongated
bands of said frame to fasten both said frame and said cover to
said base of said hard disk drive.
2. The cover of claim 1, wherein said plurality of elongated bands
extend radially outward from a central portion of said frame, each
said distal end of said elongated bands engaging said cover.
3. The cover of claim 2, further comprised of said frame being
constructed from stainless steel to prevent corrosion.
4. The cover of claim 3, further comprised of said central portion
of said frame including at least two perforations.
5. The cover of claim 1, further comprised of said frame being
formed as a single piece constituting a single unit and having at
least six outwardly protruding elongated bands.
6. A process for making a cover for a hard disk drive, comprising
the steps of:
forming a base having a mounted hard disk drive assembly comprising
an actuator, a motor driving said actuator, a disk for storing
data, and a head supported on said actuator for reading data from
said disk;
inserting a frame into a mold for said cover for said hard disk
drive, said frame being formed of a single structure constituting a
single unit and having a plurality of elongated bands that extend
radially outward to engage a plurality of edges of said cover, each
of said elongated bands having a perforation in a distal end to
fastenably engage with said base; and
injecting a plastic resin into said mold to form a cover reinforced
by said frame, said cover being molded around an end of each of
said elongated bands, said cover having a plurality of bores that
align with said perforation in said distal end of each of said
elongated bands of said frame to fasten both said frame and said
cover to said base of said hard disk drive.
7. The process of claim 6, further comprising the step of punching
a plurality of bores in said frame prior to inserting said frame
into said mold.
8. The process of claim 6, further comprised of said frame having a
plurality of elongated bands that extend radially outward from a
central portion, each said distal end of said elongated bands
engaging said cover and having a circular perforation in said
distal end of each of said elongated bands for fastening both said
frame and said cover to said base.
9. The process of claim 6, further comprised of said frame being
constructed from stainless steel.
10. A hard disk drive having a cover with improved vibrational
characteristics, comprising:
a base having a mounted hard disk drive assembly comprising an
actuator, a motor driving said actuator, a disk for storing data,
and a head supported on said actuator for reading data from said
disk;
a plate reinforcing said cover and constructed of a single piece of
stainless steel constituting a single unit, said plate having a
plurality of perforations forming a central portion in said plate
with a plurality of elongated bands radially protruding outwards to
engage said cover, said elongated bands each having a bore in a
distal end for fastenably engaging with said base; and
said cover constructed of a plastic resin material injection molded
around an end of each of said elongated bands of said plate, said
cover having a plurality of hollows that align with said bore in
said distal end of each of said elongated bands of said plate to
fasten both said plate and said cover to said base of said hard
disk drive.
11. The hard disk drive of claim 10, further comprised of said
plate having a central portion having at least two
perforations.
12. The hard disk drive of claim 11, further comprised of said
plurality of elongated bands comprising at least six elongated
bands extending outward from said central portion of said plate to
fasten to both said cover and said base of said hard disk
drive.
13. A cover for a hard disk drive having improved vibrational
characteristics, comprising:
a base having a mounted hard disk drive assembly comprising an
actuator, a motor driving said actuator, a disk for storing data,
and a head supported on said actuator for reading data from said
disk;
a frame reinforcing said cover, said frame formed of a single piece
constituting a single unit and having at least six elongated bands
that extend radially outward from a central portion of said frame
to engage a plurality of edges of said cover, each of said at least
six elongated bands having a hollow in a distal end of said each of
said at least six elongated bands to fastenably engage with said
base; and
said cover being constructed of a plastic resin material, said
edges of said cover encircling an end of each of said elongated
bands to secure said frame to said cover, said cover having a
plurality of bores that align with said hollow in said distal end
of said each of said elongated bands of said frame to fasten both
said frame and said cover to said base of said hard disk drive.
14. The cover of claim 13, each said distal end of said each of
said at least six elongated bands engaging said cover.
15. The cover of claim 14, further comprised of said frame being
constructed from stainless steel to prevent corrosion.
16. The cover of claim 15, further comprised of said central
portion of said frame including at least two perforations.
17. The cover of claim 13, further comprised of said cover being
constructed by injection molding.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cover for a hard disk drive and,
more particularly, to a cover constructed using plastic resin and a
reinforcing frame to reduce the weight of the hard disk drive
cover.
2. Background Art
Hard disk drives are widely used as auxiliary memory devices in
computer systems to magnetically record data received as a
recording apparatus for magnetically recording data received from
an external device, such as a host computer, onto a magnetic
recording medium, such as a rotating disk, or reading data that has
already been recorded on the disk. The hard disk drive includes a
housing that has a base and an attached cover, a mechanism unit
having a spindle motor for rotatably mounting the magnetic disk, a
head for reading and writing data onto the magnetic disk, an
actuator and a voice coil motor for controlling the position of the
head, and a circuit unit for performing the electrical process and
controlling the overall operation of the mechanism unit.
A hard disk drive has a magnetic head attached at the end of an
actuator arm that moves over the hard disk drive to read and write
information from the disk. The actuator pivots radially around a
shaft on a pivot bearing controlled by a voice coil motor. The disk
is rotated at high speed by a spindle motor that is attached to the
base of the hard disk drive. While the magnetic head writes or
reads data from a predetermined track of the disk, the rotation of
the disk causes the magnetic head to be hydrodynamically lifted
over the surface of the disk by an air bearing. This hydrodynamic
lifting results from the flow of air produced by the rotating disk.
This air flow causes the magnetic head to float (fly) above the
disk surface and allows the head to move over the disk while
maintaining a minute gap. During operation, when the hard disk
drive is non-operational or during a power down period, the head of
the actuator arm is held in position over a parking zone located on
the innermost track on the disk. The purpose of adjusting the
actuator arm during periods when the disk is not rotating is to
prevent data recorded on the disk from being damaged by the
magnetic head slapping against the data surface of the disk.
The hard disk drive also uses a flexible printed circuit board that
is connected via a signal cable to the magnetic head and a current
terminal of the voice coil motor. The cover of the hard disk drive
controls vibrations and other disturbances and protects the inside
of the hard disk drive by combining with the base to enclose the
hard disk drive. As such, the cover must be have sufficient
strength to endure the vibration and disturbances that occur during
operation. Another consideration when designing hard disk drive
covers is the effect of the cover on the vibrations of the hard
disk drive. As the weight of the cover increases, the first
harmonic frequency is lowered, thus making it easier for the hard
disk drive to reach a resonance condition that would interfere with
the operation of the hard disk drive.
Some covers which were developed to improve the operation of the
hard disk drive are shown, for example, in U.S. Pat. No. 5,004,207
to Ishikawa entitled Shock Mounting Structure and Magnetic Disk
Apparatus, U.S. Pat. No. 4,967,293 to Aruga entitled
Multi-Positioner Magnetic Disk Storage Apparatus Having Means for
Reducing Mechanical Vibration Interference Between Positioners,
U.S. Pat. No. 5,223,996 to Read entitled Combined Shock Mount Frame
and Seal for a Rigid Disk Drive, U.S. Pat. No. 5,703,734 to
Berberich entitled Disc-Drive Having an Integral Gasket and
Continuous Outer Perimeter Shock Bumper, and U.S. Pat. No.
5,535,092 to Bang entitled Apparatus for Reducing Impacts on a Hard
Disk Assembly. Contemporary hard disk drive covers are unable to
produce a cover with improved vibrational characteristics without
requiring expensive machining or special anti-corrosive coatings.
Manufacturers have also tried changing the shape of the hard disk
drive cover to a more simple design using a press, but that has not
led to a difference in the weight of covers and to an improvement
in the vibrational characteristics of the hard disk drive.
U.S. Pat. No. 5,025,335 to Stefansky entitled Architecture for 21/2
Inch Diameter Single Disk Drive, mentions a disk drive cover and
bottom made out of injection molded plastic that uses a combination
of mounting posts and a closed loop, embedded servo tracking system
to compensate for the lack of structural rigidity of plastic. The
combination of the two adjustments is an improvement of several
existing components to compensate for the vibrational
characteristics of a plastic housing, rather than a new structural
design to improve the vibrational characteristics. The
manufacturing of a cover with mounting posts that mate with a
printed circuit board increases the cost of manufacturing while
reducing the amount of dimensional tolerance that can occur without
interfering with the assembly of the disk drive.
Currently, the majority of hard disk drive manufacturers use a
die-casting method and aluminum material to produce a cover. Since
the aluminum die-casting process uses an injection molding process,
pores are formed in the inside that can change the properties of
the aluminum material and cause either corrosion or outgasing. To
compensate for this deficiency, an E- coating technique is often
used after the injection molding process. Not only does the
E-coating technique raise the cost of production, but due to out
gassing problems manufacturers are trying to find another coating
technique. Due to the dimensional imprecision of die-casting, a
cover is not ready for use until it has been machined after
injection into the die cast. The machining of the cover causes
contamination in the inside of the hard disk drive, thus lowering
the reliability of the hard disk drive, or in a clean room due to
particles that have been machined off of the hard disk drive.
Additionally, the required machining process further increases the
cost of producing the hard disk drive.
Die-casting using a magnesium material has also been developed to
try to improve the vibrational characteristics of the hard disk
drive, but magnesium's susceptibility to corrosion has made it
problematic to use a cover substantially composed of magnesium.
Hard disk drive manufacturers continue to make every possible
effort to minimize vibrational characteristic problems while
providing the necessary protection to the hard disk drive, but it
is still not easy to find a solution to the problem.
I believe it may be possible to provide a hard disk drive that is
an improvement over those currently used by manufacturers. A hard
disk drive that is made of a light weight material and reinforced
with a frame, that does not use the die cast method, that does not
require using machining, and that does not require an expensive
coating process would decrease the cost of manufacturing the hard
disk drives, that does not require the extra steps involved with
using mounting posts, that can use plastic of a lower rigidity than
otherwise possible if not for the reinforcing frame, that improves
the reliability of hard disk drives using plastic covers, and
improves the vibrational characteristics of hard disk drives.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an
improved plastic resin hard disk cover.
It is another object to provide a hard disk drive cover that has
increased dimensional precision, thus eliminating the machining
step during the assembly of the hard disk drive.
It is still another object to provide a hard disk drive cover that
has improved vibrational characteristics.
It is yet another object to provide a hard disk drive cover that
has good anti-corrosive properties, thus eliminating the need to
apply a special coating to the hard disk drive cover.
It is still yet another object to provide a hard disk drive cover
that has a reduced cost of production.
It is a further object to provide a hard disk drive cover that
increases the efficiency of hard disk drive production.
It is a further object to provide a hard disk drive cover that can
use plastics previously unsuitable for use as hard disk drive
covers due to an improved apparatus for increasing rigidity.
It is a further object to provide a hard disk drive cover that
improves the vibrational characteristics of injection molded
plastic without increasing the dimensional precision that must be
maintained throughout the assembly process.
These and other objects can be achieved by constructing a hard disk
drive using a plastic resin and a stainless steel or alloy frame.
The plastic resin is lighter than conventional metallic covers,
thus lowering the weight of the hard disk drive. By lowering the
weight of the hard disk drive, the resonant frequencies are
increased, thus improving the vibrational characteristics of the
hard disk drive. The frame is inserted over the disk drive to
reinforce the cover and increase its rigidity without overly
increasing the weight of the hard disk drive. The cover can be
constructed using plastic injection molding. This allows the cover
to be constructed with improved dimensional accuracy, superior to
that of die-casting. The frame has perforations to decrease weight
and a plurality of elongated portions that are fastened at contact
points between the base and the cover of the hard disk drive.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of this invention, and many of the
attendant advantages thereof, will be readily apparent as the same
becomes better understood by reference to the following detailed
description when considered in conjunction with the accompanying
drawings in which like reference symbols indicate the same or
similar components, wherein:
FIG. 1 is an exploded perspective view of a hard disk drive with
its cover removed;
FIG. 2 is a plan view of the frame that is mounted in a hard disk
drive constructed according to the principles of the present
invention;
FIG. 3 is a bottom view of the cover of FIG. 2 with a frame mounted
to the cover for a hard disk drive;
FIG. 4 is a perspective view of the cover of FIG. 2 with a
reinforcing frame attached.
DETAILED DESCRIPTION OF THE DRAWINGS
Turning now to the drawings, FIG. 1 illustrates a hard disk drive
that has magnetic head 5 attached at the end of actuator arm 4 that
moves over the hard disk drive to read and write information from
disk 2. Actuator arm 4 pivots radially around shaft 3 that is on a
pivot bearing controlled by voice coil motor 8. Disk 2 is rotated
at high speed by spindle motor 1 that is attached to the base of
the hard disk drive. While magnetic head 5 writes or reads data
from a predetermined track of disk 2, the rotation of the disk 2
causes magnetic head 5 to be hydrodynamically lifted over the
surface of the disk 2 by an air bearing. This hydrodynamic lifting
results from the flow of air produced by the rotating disk 2. This
air flow causes magnetic head 5 to float (fly) above disk 2's
surface and allows magnetic head 5 to move over disk 2 while
maintaining a minute gap. During operation, when the hard disk
drive is non-operational or during a power down period, magnetic
head 5 of actuator arm 4 is held in position over a parking zone
located on the innermost track on disk 2. The purpose of adjusting
actuator arm 4 during periods when disk 2 is not rotating is to
prevent data recorded on the disk 2 from being damaged by magnetic
head 5 slapping against the data surface of disk 2.
The hard disk drive also uses a flexible printed circuit board 21
that is connected via signal cable 7 to magnetic head 5 and a
current terminal of the voice coil motor 8. Cover 10 of the hard
disk drive controls vibrations and other disturbances and protects
the inside of the hard disk drive by combining with the base to
enclose the hard disk drive.
The cover as constructed according to the principles of the present
invention utilizes a plastic material that is reinforced by a frame
that is attached to the inside of the cover. This frame is shown in
FIG. 2. FIG. 3 shows a bottom view of a cover with a frame mounted
inside and FIG. 4 is shows a top view of a cover that has a
reinforcing frame attached.
Cover 10 (FIG. 3) is engaged with base 9 (FIG. 1) and constructed
from plastic resin using an injection molding process to allow the
dimensional accuracy of the cover 10 to be improved. To increase
the rigidity of the plastic material, a steel or alloy frame 11
(FIG. 2) can be attached inside cover 10. Cover 10 is formed
integrally with frame 11 to intensify the rigidity of cover 10 and
prevent corrosion.
As shown in FIG. 2, frame 11 has reinforcement portion 13, that has
two holes 12 formed inside, and elongated extended bands 14.
Preferably, there are 6 elongated extended bands that extend
radially outward from reinforcement portion 13. Each of extended
bands 14 has hole 12 positioned near a distal end to engage the
inner side of cover 10 (FIG. 3) and the upper side 22 of base 9
(FIG. 1).
The cover 10 is manufactured using the injection molding process.
Holes 12 are formed in frame 11 by using intermediate insertions,
driven by a press, that perforate through the surface of frame 11.
Frame 11 may be constructed from stainless steel to intensify the
rigidity of cover 10 and prevent corrosion of the frame. Frame 11
is perforated using a press and inserted in a mold of cover 10.
Then a material that is not susceptible to vibration, such as resin
or VECTRA, is injected into the mold, thus forming the vibration
resistant material into the shape of cover 10. VECTRA is a
thermoplastic material with a Rockwell hardness of 84 on an M scale
and a tensile impact strength of 2,300 J/m. At normal temperatures
the strength and modulus values for VECTRA are high and comparable
with those of ABS resins. As shown in FIG. 4, cover 10 is formed
around the ends of frame 11, while fastening holes 15 in the cover
are aligned with holes 12 in frame 11 to secure the cover and the
frame to the base of the hard disk drive.
As previously discussed, cover 10 may be formed using a plastic
material. More specifically, it is preferable to use an
anti-vibration plastic resin material. This allows cover 10 to be
used as a component for absorbing vibration and also reduces the
weight of cover 10. The reduction of the weight of cover 10 makes
the cover's resonance point increase, thus improving the vibration
characteristics of the hard disk drive. In addition, the use of a
stainless steel frame 11 further increases the rigidity of the
cover 10. This reinforces the otherwise weaker portions of cover
10. Cover 10's high dimensional accuracy, due to the injection
molding process, eliminates the need to do any machining of the
cover 10 before completing the assembly of the hard disk drive.
This will reduce the cost of production and prevent the
contamination of hard disk drives by particles of the cover 10 that
are machined off of the cover 10 to bring its dimensions within
predetermined tolerances. Furthermore, the use of a plastic resin
coating eliminates the out gassing problem, thus eliminating the
necessity of applying a special coating to the cover 10.
As described above, the hard disk drive cover of the present
invention achieves increased dimensional precision by using
injection molded plastic methods. The plastic resin cover is able
to attain the requisite rigidity due to the insertion of a
reinforcing frame. The rigidity increases the ability of the hard
disk drive to endure vibrations and other disturbances, while the
decrease in weight, due to use of a plastic resin to form the
cover, causes the resonance point to increase. This improves the
vibrational characteristics of both the cover and the hard disk
drive. Furthermore, the present invention reduces manufacturing
costs by eliminating the need to machine the cover prior to
assembly and also eliminating the need to apply a special
anti-corrosive coating to the cover.
Although this preferred embodiment of the present invention has
been disclosed for illustrative purposes, those skilled in the art
will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying claims. It
is also possible that other benefits or uses of the currently
disclosed invention will become apparent over time.
* * * * *